import pandas as pd

# 方式一：指定列的值
df1 = pd.DataFrame({
    "a": [4, 5, 6],
    "b": [7, 8, 9],
    "c": [10, 11, 12]
}, index=[1, 2, 3])

# 方式二：指定每个单元格的值
df2 = pd.DataFrame([
    [4, 7, 10],
    [5, 8, 11],
    [6, 9, 12]
], index=[1, 2, 3], columns=['a', 'b', 'c'])

# 从字典列表创建DataFrame
data = [
    {'a': 4, 'b': 7, 'c': 10},
    {'a': 5, 'b': 8, 'c': 11},
    {'a': 6, 'b': 9, 'c': 12}
]
df3 = pd.DataFrame(data)
print(df1,df2,df3)